Drying-furnace.



'No. 731,619. PATEN'I'ED JUNE 23, 1903. L. E. RODGERS & J. 0. TRAUTWBI'N. DRYING FURNACE.

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No 731,619. I PATENTED JUNE 28, 1903. L. E. RODGERS & J. 0. TRAUTWEIN.

DRYING FURNACE.

APPLICATION nun MAR. 2a, 1903.

no 14019121.. 2 sums-sum 2 To all whom it may concern/.- I t I Be it knowirthat we, .LoUIs E. RODGERS- uelrsneier UNITED STATES Patented June 23, 1903.

TENT FFICE,

DRYING-FURNACE.

SPECIFICATION forming part of Letters Patent No. 731,619,dated'June 23, 1903. Application filed March 26,1903. Serial No. 149,654.. (No model.)

and JACOB O. TRAUTWEIN, citizens of the .United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Drying-Furnaces, of which the following is a I specification.

Our invention relates to improvements in furnaces or stoves adapted for general drying purposes, and more especially for supplying heat to dry-kilns for drying brick and other clay products.

When brickor the like have been molded fromthe clay, itisfthe common practice as a step in the process of man ufactureprevious to burning or firing to subject them in the dry-kilns to a preliminary drying operation. In the larger plants where a waste-heat system is used it is usual. to employ a series of burning-kilns connected by a common airtunnel, .into which air maybe drawn. from such of the burning-kilns as maybe cooling at the time and-from which it-maybe dis-l charged into kilns Wherethe clay products are being dried. The utilization of the waste heat from the burning-kilns-while coolingto dry brick or other clay products in the drykilns is naturallythe most economical way of performing the drying operation; but there are occasions even at the larger plantswhenf at the time a charge. me drying-kiln is to be dried no charge in any burning-kiln. is in readiness for cooling, which to avoid delays necessitates the supplying of heat for the dry ing operation from some other source. Ourobject is to provide an air-heatingstove or furnace of simple and improved construction for use more ,especiallyin drying brick and other clay products and which will op-j erate to deliver a large volume of heatedair.

and gases substantially free from soot and at a comparatively small expense of fuel.

In the drawings, Figure 1 is a longitudinal section taken'on line 1 .in Fig. 3 through our improved furnace, which is shown located at the mouth of a tunnel provided with a suitablefan; Fig. 2, a partial plan section on line 2 in Fig. l, and-Fig.3 a viewshowing to the right a section at the forward end of the furnace on line 3in Fig. 1 and to the left a section on line 3 in Fig. 1.

wall.

:the rear of the latter.

The furnace is constructed, preferably, in a pit A, for convenience and economy, atthe mouth of a tunnel or conduit linebeing at on. r .C is the front wall of the furnace, and D a bridge-wall, between which is a fire-chamber E, provided with a grate a. Draft-supply pipes 12 I) extend from above the ground-line to the ash-chamber beneath the grate a. Beyond the bridge-Wall isa hanging wall orarch F, presenting a wall extending downward from the furnace-top V to a plane somewhat below that of the top of the bridge-wall, leaving the passage 0. Beyond the wall or arch F is aWa1lG,someWhat higher than the bridgewall and constructed to leave thepassage d. In thewall Gare openings 6, extending to a chamber H,beyond which is the rear wall I of the furnace. The wallI extends nearly to B, the'groundthe'top V, leaving an outlet f to the tunnel B.

Extending through openings in the front wall C and arch F and terminating at the rear of thearc h F'is a series ofhorizontal air-conducting pipes- K, crossing the fire-chamber just above the plane ofthe top of the bridge- Wall*O,- arch F, and wallG, terminating at A third series of similar pipes M extends through the Wall 0, arch :F, across the top of the wall-G, andthrough the rearrwall I, where lthey terminate, and

fourth series of similar pipes N extends through openings inthe wall (land arch F and rest at their rear ends on the wall I in the space f.

The construction shown and described is designed to eifect approximately complete combustion of fuel and to cause the resultant 1 hot gases mixed with a large volume of highlyheatedair to'be discharged into the tunnel B.

Located in or at the end of the tunnel isa suitable fan P, which maybe driven by a belt. (Not shown.) Fuel is fed to the grate a through the door It, 2' being the deorof the ashpit. An artificial draft'iscreated by the fan P. Air to support combustion-is dr awn downward through the draft-supplypipes I), and the hot products of combustion move along the nndulatingpassage,over theibridgewall D, and through the spaces 0, d, andf to the tunnel. As the hot products of combustion rise from the fire-chamber E they heat the pipes K L MNand the air passing through A second series of similar air-conduct- .ing pipes L extendsthrough openings in the ICC the said pipes fromthe forward end of the furnace. The airin the lower series of pipes K mingles with the hot products of combustion between the arch I and wall G and, being intensely hot, tends to aid in facilitating combustion of any unconsumed carbon that is present in the hot products of combustion. The latter mingled with the hot air from the series of pipes K pass over the wall G and through the openings 6, where they mingle with a second volume of highly-heated air passing through the pipes L, which also tends to further the combustion of carbon particles in the chamber H. After passing through the outlet f the hot products of combustion mixed with air, as described, and substantially free from unconsulned particles mix in the tunnel with the more or less highly heated air which is drawn through the pipes M N, the mixture of gases and air being forced through the tunnel by the fan P.

The kiln or kilns in which the drying of clay products is to be efiected would be thrown into open communication with the tunnel B to receive the heated mixture of gases and air in the usual way.

In order to retard the passage of the hot products of combustion, and thus facilitate heatingof the air-conducting pipes, we prefer to provide baffles or retarding-plates R between the pipes K Lover the space between the bridge-wall and arch F and also between the pipes L M at the space between the arch and wall G. The plates R may be formed, for example, as shown in Fig. 2, with series of openings t' over the spaces between the pipes on which they rest. To break up the air-currents discharged from the air-conducting pipes, we prefer to provide grids S over the rear ends of the pipes. These grids may be sheets of expanded metal, supported to extend as shown. They tend not only to break up the air-currents and facilitate the mixing thereof with the hot products of combustion, but also retard the air-currents in the air-conducting pipes to prolong the subjection thereof to the heat.

The large volume of air and gases drawn by the fan into the tunnel and discharged to the drying-kilns, as described, is substantially free from soot and very high in temperature. By reason of the fact that approximately perfect combustion of the fuel takes place only a minimum quantity of coal need be fed to the furnace to insure the desired volume of mixed air and gas at the desired temperature.

Secured against the front wall 0 of the furnace is a shield or guard T of the form shown.

It is located above the furnace-door h, beingclosed at the bottom and open at the top. It permits fresh air from above to pass freely to the air-conducting pipes, but prevents the dust and ashes when drawn out of the ashpit from being sucked by the air-currents into said pipes.

While we prefer to construct our improvements throughout as shown and described, they may be variously modified in the matter of details of construction without departing from the spirit of our invention as defined by the claims.

What we claim as new, and desire to secure by Letters Patent, is-

1. In a drying-furnace of the character described, the combination with a'conduit and fan, of a fire-chamber and an undulating passage for the hot products of. combustion extending from the fire-chamber to said conduit, and a horizontally-disposed series of airconducting pipes extending from the front of the furnace across the fire-chamber and discharging into said undulating passage, substantially as and for the purpose set forth.

2. In a drying-furnace of the character described, the combination with a conduit and fan, of a fire-chamber, bridge-wall, and an undulating-passage for hot products of combustion beyond said bridge-wall extending to said conduit, and a horizontal series of parallel air-conducting pipes extending from the front of the furnace across the fire-chamber and discharging at different points along said undulating passage, substantially as and for the purpose set forth.

3. In a drying-furnace of the character described, the combination with a conduit and fan, of a fire-chamber and an undulating passage vfor the hot products of combustion extending from the fire-chamber to said conduit, a seriesof air-conducting pipes extending from the front of the furnace across the fire-chamber and discharging into said und ulating passage, and draft-retarding baflies in said undulating passage, substantially as and for the purpose set forth.

4. In adrying-furnace of the character described, the combination with a conduit and fan, of a fire-chamber and an undulating passage for hot products of combustion extending from the fire-chamber to said conduit, se-

ries of air-conducting pipes extending from the front of the furnace across the fire-chamber and discharging into said undulating passage, and grids over the mouths of said airconducting pipes at the discharge ends, substantially as and for the purpose set forth.

5. A drying-furnace formed with a front wall 0, fire-chamber E, bridge-wall D, arch F, and walls G, I, a series of air-conducting pipes extending from the wall 0 and terminating at the arch F, a series of air-conducting pipes extending from the wall 0 through the said arch and terminating at the wall G, and series of air-conducting pipes extending from the wall 0 through the said arch over the wall G and terminating at the Wall I, all constructed and arranged to operate substantially as and for the purpose set forth.

LOUIS E. RODGERS. JACOB O. TRAUTWEIN. In presence of- WALTER N. WINBERG, M. S. MACKENZIE.

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